If John McCain left the GOP in 2001, what would have happened?

[NewYorkExpress]

If McCain runs as a Democrat in 2004, he loses in the primary, possibly to Janet Napolitano or Ed Pastor.

If McCain runs as an Independent in 2004, he finishes second in a three-way race, but draws most of his vote from the Democratic nominee, losing to someone like Jeff Flake.

If McCain decides to run as a Democrat for President in 2004, he probably makes it to Iowa on name recognition alone, but he'd have trouble raising money and attracting support because of how conservative he is. A close comparison in the IRL 2004 race might actually be Howard Dean, who was relatively moderate and had to dramatically move to the left to be competitive.

If McCain runs for President as an Independent, he finishes third, but does well enough in both the both the popular vote and in key battleground states to tip the election to Kerry. His running mate is probably a high-profile moderate like Angus King, or someone who gets along with him personally, like Joe Lieberman.